A conventional walk-behind reversible soil compactor includes a frame that carries a generally horizontal compaction plate which is adapted to engage and compact the soil, or other material. To provide a vibratory compacting action, a pair of shafts are journaled for rotation on the frame and each shaft carries an eccentric weight. A power source, such as a gasoline engine, is mounted on the frame and the drive shaft of the engine is connected to the eccentric shafts through a gear system which is arranged so that the eccentric shafts rotate simultaneously and in opposite directions.
To provide forward and rear movement for the compactor, the phase relationship of the weights on the eccentric shafts is changed by a shifting mechanism. The shifting mechanism, as used with a conventional walk-behind compactor, is very complex, and as the shifting mechanism is directly associated with the eccentric shafts, the shifting mechanism is subjected to intense vibration and therefore has a relatively short service life.
As a further problem, as the eccentric shafts are continuously rotating in opposite directions, torque generated by one shaft will oppose the torque generated by the second eccentric shaft. Because of this and the increased weight resulting from the shifting mechanism, the speed of travel of the compactor over the soil is substantially reduced over a similarly powered unidirectional compactor.
Therefore, the reversible walk-behind, vibratory soil compactors as used in the past, have been relatively expensive due to the requirement of a complex shifting mechanism, have had a relatively low speed of travel, and have been subject to high maintenance costs.